The most basic function of refrigerators is to preserve food at a low temperature such that it can be taken out therefrom. For this purpose, a refrigerator is generally comprised of, for example, a body, a heat insulating door hinged to the body so as to be capable of opening and closing the entrance to the body, and a seal strip formed on the door and coming into sealing engagement with the fringe of the body surrounding the entrance to the body when the door is closed. The body consists of an outer box and an inner box, a heat insulating layer filled in a space formed between the boxes. The seal strip formed on the cabinet acts to prevent the cooled air in the body from leaking when the door is closed.
Of course, the leakage of the cooled air cannot be sufficiently prevented by the seal strip unless the fringe of the body which surrounds the entrance to the body and with which the seal strip comes into sealing engagement is uniform. Usually, the fringe of the body of a refrigerator surrounding the entrance to the body is provided with front marginal flanges for the top wall and the both side walls of its outer box, respectively, each front flange bending inwardly to right angles. Accordingly, making the fringe surrounding the entrance uniform depends to a large measure on the manner in which the front flange on the top wall is connected to the neighboring front flanges on the side walls at the abutting corners.
In a conventional refrigerator as disclosed in Japanese Utility Model Publication No. 12755/1971, one of the front flange on the top wall and each front flange on the side walls is offset so that the other may be placed on the one front flange. Then, the portions stacked on top of each other are centrally connected together by spot-welding. During this welding operation, a pressure is applied to some portions of the overlapping front flanges, and therefore there arises a possibility that the front end portion of the overlying flange is bent back toward the front, whereby the fringe is made nonuniform. Further, because such a front end portion is formed by cutting out a steel sheet and because it is used around the entrance that users most frequently touch, they might be hurt thereby. Furthermore, the prior art refrigerator cannot be fabricated from a flat steel sheet already coated with paint, whether it has been blanked or not. Consequently, a steel sheet cannot be coated before it is bent into a three-dimensional outer box and spot-welded as described above. Thus, inefficient spraying operation is required.
Another kind of refrigerator has been proposed as by Japanese Utility Model Laid-Open Nos. 100988/1980 and 90752/1979, in which the front flange on the top wall is opposed to the front flanges of the sides walls with a space therebetween at each corner. The opposing ends are offset or stepped, and a corner piece of synthetic resin is inserted in the space so that the space is sealed and the end portions of the neighboring flanges are flush with each other, and then they are joined together.
The refrigerator described just above is advantageous in that its outer box can be formed out of a flat steel sheet already coated with paint. However, it is difficult to hold neighboring flanges in flush state, because they do not overlap directly. Another problem is that the number of components as well as the number of steps needed to fabricate it is large.